Cloning of gag gene of HIV-1 subtype C (Indian strain) into a mammalian expression vector and in vitro expression studies.

PURPOSE: Acquired immunodeficiency syndrome caused by HIV-1 is one of the biggest health problems we are facing today. It is required to concentrate efforts towards designing a safe, effective and affordable vaccine candidate in the context of the growing epidemic worldwide. Recently the approach of DNA based immunogen has evoked a lot of enthusiasm in the preclinical models. METHODS: This study was designed towards a subtype C based gag DNA construct in the expression vector pJW4304. The gag and protease genes of HIV-1 subtype C were cloned into a mammalian expression vector pJW4304. The cloning strategy was designed so as to express a naturally processed form of the protein. Expression of gag protein by the construct pJWgagprotease49587 was evaluated by western blotting, p24 antigen capture ELISA and electron microscopy. RESULTS: Gag p24 was detected both in the supernatant and in the transfected cells. Extra cellular p24 protein was estimated by p24 antigen capture ELISA. Immunoblotting using HIV positive polyclonal sera further confirmed the expression and processing of gag gene. The 24kDa band has been observed in cell lysates, which indicates that the proper processing is taking place in the presence of protease. Virus like particles were seen budding from the cell membrane 24 and 48 hours post transfection by transmission electron microscopy. CONCLUSIONS: The recombinant construct pJWgagprotease49587 has shown good expression in vitro and therefore is a good candidate to study immunogenicity of the construct. Immunogenicity testing in mice is being carried out currently with this construct.

Predictor of outcome of hyperthyroidism due to Graves disease: serum triiodothyronine/thyroxine ratio.

There is a proportionally greater increase in the serum T3 than Serum T4 concentration in patients with hyperthyroidism due to Grave's disease which results in an elevation of serum T3 to T4 ratio. The study was undertaken to investigate the alteration of serum T3 to T4 ratio in relation to the outcome of antithyroid drug therapy. 98 patients of hyperthyroid Grave's disease were studied and 78 patients had T3 to T4 ratio greater than 20 ng/microgram before therapy (normal range 14-20; mean 16.0) In 16 out of 78 patient T3 to T4 ratio remained high during a 18 months course of antithyroid drug therapy and in 13 of them (81%) hyperthyroidism recurred after stoppage of treatment. In the remaining 62 patients, the initial high T3 to T4 ratio became normal (< 20) during treatment and 34 of them (54.9%) had a remission of the disease after stoppage of the drug. Of the 20 patients in whom the initial T3 to T4 ratios were within normal range, the ratio remained normal during treatment and 16(80%) had a remission. Goiter size was larger in patients with high serum T3 to T4 ratio and reduction of goiter size occurred in some patients (59%) with decreasing T3 to T4 ratios. It is concluded that serum T3 to T4 ratio is a single and a useful predictor of the outcome of antithyroid drug therapy in patients with hyperthyroidism due to Grave's disease. A ratio greater than 20 throughout therapy indicates that the chances of relapse is high and a ratio below 20 either initially or during therapy is an indication of prolonged remission.

Evaluation of long-term results of two schedules of treatment for toxic multinodular goitre with radioiodine therapy (I 131).

Results of the long term effects of two schedules of radioine therapy (I131) in 130 toxic multinodular goitre patients were evaluated. Seventy five patients (group I) were treated with low doses and 55 patients (group II) with calculated high doses adjusted for thyroid weight (0.5-1 mu ci/g) and radioiodine uptake. Follow up (mean +/- SEM) was 4.5 +/- 0.4 years and 4.8 +/- 0.6 years respectively (p > 0.1). At the end of followup hyperthyroidism was successfully reversed in 87% (Group I) and 82% (Group II). In group I hypothyroidism was present in 5% of patients while it was 12.5% in group II patients. The total dose per gram of thyroid tissue was not significantly different in both the groups (0.058 mu ci +/- 0.0054 VS 0.073 +/- 0.0054 ci/g.) However in group II the number of I131 administration was significantly lower (1.5 +/- 0.2) than in group I (3.2 +/- 0.4) and the percentage of patients who were adequately treated in Group II with single dose was more as compared in group I (62% in group II versus 49% in group I) Hypothyroidism was reached in a shorter time after treatment in group II (median time 0.8 year in group II Vs 1.1 yrs in group I). Patients with positive thyroid antibodies showed a significant earlier development of hypothyroidism within six months. It is concluded that radioiodine is an effective treatment for toxic multinodular goitre with a significant low incidence of post therapy hypothyroidism in patients treated with low doses as compared to higher doses of radioiodine therapy.

Long-term results of two schedules of treatment for toxic multinodular goitre with radioiodine therapy.

Results of the long-term effects of two schedules of radioiodine therapy I131 in 130 toxic multinodular goitre patients were evaluated. Seventy five patients (group I) were treated with low doses and 55 patients (group II) with calculated high doses adjusted for thyroid weight (0.5-1 mci/g) and radioiodine uptake. Follow up (mean +/- SEM) was 4.5 +/- 0.4 years and 4.8 +/- 0.6 years respectively (P > 0.1). At the end of follow up, hyperthyroidism was successfully reversed in 78% (Group I) and 82% (Group II). In group I hypothyroidism was present in 5% of patients, while it was 12.5% in group II patients. The total dose per gram of thyroid tissue was not significantly different in both the groups (.058 mci +/- .0054 VS .073 +/- .0054 mci/g). However in group II the number of I131 administration was significantly lower (1.5 +/- 0.2) than in group I (3.2 +/- 0.4). The percentage of patients who were adequately treated in Group II with single dose was more as compared in group I (62% in group II versus 40% in group I). Euthyroidism was reached in a shorter time after treatment in group II (median time 0.8 year in group II Vs 1.1 yrs in group I) It is concluded that radioiodine is an effective treatment for toxic multinodular goitre with a significant low incidence of post therapy hypothyroidism in patients treated with low doses as compared to higher doses of radioiodine therapy.